hv: dynamically configure CPU affinity through hypercall

- add a new member cpu_affinity to struct acrn_create_vm, so that acrn-dm
  is able to assign CPU affinity through HC_CREATE_VM hypercall.

- if vm_create.cpu_affinity is zero, hypervisor launches the VM with the
  statically configured CPU affinity.

Tracked-On: #4616
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

Author: ZideChen0

hypervisor/common/hypercall.c

@@ -166,21 +166,35 @@ int32_t hcall_create_vm(struct acrn_vm *vm, uint64_t param)
 			/* Filter out the bits should not set by DM and then assign it to guest_flags */
 			vm_config->guest_flags |= (cv.vm_flag & DM_OWNED_GUEST_FLAG_MASK);
 
-			/* GUEST_FLAG_RT must be set if we have GUEST_FLAG_LAPIC_PASSTHROUGH set in guest_flags */
-			if (((vm_config->guest_flags & GUEST_FLAG_LAPIC_PASSTHROUGH) != 0U)
-				&& ((vm_config->guest_flags & GUEST_FLAG_RT) == 0U)) {
-				pr_err("Wrong guest flags 0x%lx\n", vm_config->guest_flags);
+			/* post-launched VM is allowed to choose pCPUs from vm_config->cpu_affinity_bitmap only */
+			if ((cv.cpu_affinity & ~(vm_config->cpu_affinity_bitmap)) != 0UL) {
+				pr_err("%s: Post-launch VM can't share PCPU with Pre-launch VM!", __func__);
 			} else {
-				if (create_vm(vm_id, vm_config, &target_vm) != 0) {
-					dev_dbg(DBG_LEVEL_HYCALL, "HCALL: Create VM failed");
-					cv.vmid = ACRN_INVALID_VMID;
-				} else {
-					/* return a relative vm_id from SOS view */
-					cv.vmid = vmid_2_rel_vmid(vm->vm_id, vm_id);
-					cv.vcpu_num = vm_config->vcpu_num;
+				/* DM could overwrite the statically configured PCPU bitmap */
+				if (bitmap_weight(cv.cpu_affinity) != 0U) {
+					vm_config->vcpu_num = bitmap_weight(cv.cpu_affinity);
+					vm_config->cpu_affinity_bitmap = cv.cpu_affinity;
 				}
 
-				ret = copy_to_gpa(vm, &cv, param, sizeof(cv));
+				/*
+				 * GUEST_FLAG_RT must be set if we have GUEST_FLAG_LAPIC_PASSTHROUGH
+				 * set in guest_flags
+				 */
+				if (((vm_config->guest_flags & GUEST_FLAG_LAPIC_PASSTHROUGH) != 0UL)
+					&& ((vm_config->guest_flags & GUEST_FLAG_RT) == 0UL)) {
+					pr_err("Wrong guest flags 0x%lx\n", vm_config->guest_flags);
+				} else {
+					if (create_vm(vm_id, vm_config, &target_vm) != 0) {
+						dev_dbg(DBG_LEVEL_HYCALL, "HCALL: Create VM failed");
+						cv.vmid = ACRN_INVALID_VMID;
+					} else {
+						/* return a relative vm_id from SOS view */
+						cv.vmid = vmid_2_rel_vmid(vm->vm_id, vm_id);
+						cv.vcpu_num = vm_config->vcpu_num;
+					}
+
+					ret = copy_to_gpa(vm, &cv, param, sizeof(cv));
+				}
 			}
 		}
 	}

hypervisor/include/public/acrn_common.h

@@ -360,8 +360,15 @@ struct acrn_create_vm {
 
 	uint64_t req_buf;
 
+	/**
+	 *   The least significant set bit is the PCPU # the VCPU 0 maps to;
+	 *   second set least significant bit is the PCPU # the VCPU 1 maps to;
+	 *   and so on...
+	*/
+	uint64_t cpu_affinity;
+
 	/** Reserved for future use*/
-	uint8_t  reserved2[16];
+	uint8_t  reserved2[8];
 } __aligned(8);
 
 /**